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Statistics
Andy Sharma
44
Other
Graduate
04/29/2013

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Term
Quantitative Analysis
Definition
an analysis technique applying mathematics (suffers from the unobserved)Intervals w/o natural zero ratio with natural zero
Term
Qualitative Analysis
Definition
an inquiry into the reasoning behind human behavior
Term
Probability:
Definition
likelihood of some event occurring
Term
Statistics
Definition
Collecting, gathering, organizing data analyzing data from a sample and generalize it to a population
Term
Random Variable
Definition
is a variable whose value is subject to variations due to chance
Term
Cumulative distribution function
Definition
The cumulative distribution function of a real-valued random variable X is the function given by

where the right-hand side represents the probability that the random variable X takes on a value less than or equal to x. The probability that X lies in the semi-closed interval (a, b], where a < b, is therefore
Term
Probability distribution function
Definition
Dummy variable – type of variable known as nominal or categorical variable 0,1
Term
Measurement error
Definition
Difference between the actual value of a quantity and the value obtained by a measurement.
Term
experimental group/treatment group
Definition
An experimental group is the group in a scientific experiment where the experimental procedure is performed. This group is exposed to the independent variable being tested and the changes observed and recorded.
Term
control group
Definition
A control group is a group separated from the rest of the experiment where the independent variable being tested cannot influence the results.
Term
Population
Definition
represents all the members of a group/interest
Term
Sample
Definition
A collection of cases selected from a larger population
Term
Ordinal Variable
Definition
Variables measured with numerical values where the numbers are meaningful (2 is larger than 1) but the distance between the numbers is not constant.
Term
Nominal Variable:
Definition
labels are used to identify different levels of a variable
Term
Interval/Ratio variable:
Definition
Variables measured with numerical values with equal distance, or space between each number (e.g. 2 is twice as much as 1, 4 is twice as much as 2, the distance between 1 and 2 is the same as the distance between 2 and 3)
Term
Categorical Variable
Definition
when variables are measured using categories or names (dummy)
Term
Discrete Variable
Definition
cannot take on all values within the limits of the variable
Term
Continuous Variable
Definition
Variables that can take on any value
Term
Correlation
Definition
A mutual relationship or connection between two or more variables
Term
Causation
Definition
the concept that variation in one variable causes variation in another variable
Term
Panel Data
Definition
refers to multi-dimensional data frequently involving measurements over time
Term
Cross-Sectional Data
Definition
Cross-sectional data refers to data collected by observing many subjects (such as individuals, firms or countries/regions) at the same point of time, or without regard to differences in time.
Term
Time-Series Data
Definition
s a sequence of data points, measured typically at successive points in time spaced at uniform time intervals.
Term
Uniform Distribution
Definition
A distribution that has one value that have the highest frequency of scores
Term
Normal Distribution
Definition
A bell-shaped frequency distribution of scores that has the mean, median, and mode in the middle of the distribution and is symmetrical and asymmetrical
Term
Negative distribution/ Skew
Definition
In a skewed distribution, when most of the scores are clustered at the higher end of the distribution with fewer scores creating a tail at the lower end of the distribution
Term
Binomial Distribution
Definition
A distribution that has two values that have the highest frequency of scores
Term
Poisson distribution
Definition
is a discrete probability distribution that expresses the probability of a given number of events occurring in a fixed interval of time and/or space if these events occur with a known average rate and independently of the time since the last event.[1] The Poisson distribution can also be used for the number of events in other specified intervals such as distance, area or volume
Term
Mean
Definition
The arithmetic average of a distribution of scores- add up all the numbers, then divide by how many numbers there are.- adding/summing all the scores in a distribution and dividing by the number of scores
Term
Median
Definition
The score in a distribution that marks that 50th percentile. It is the score at which 50% of the distribution falls below and above 50% fall above
Term
Mode
Definition
The score in the distribution that occurs most frequently Score that appears the most/ most common score, most frequent
Term
Variance
Definition
The sum of the squared deviations divided by the number of cases in the population, or by the number of cases minus one in the sample
Term
Range
Definition
The difference between the largest score and the smallest score of a distribution
Term
Standard Deviation
Definition
Tells us about variation (the larger the sample the smaller the Standard Deviation)
Term
skewness
Definition
When a distribution of scores has a high # of scores clustered at one end of the distribution with relatively few scores spread out toward the other end of the distribution, forming a tail
Term
Kurtosis
Definition
The shape of a distribution of scores in terms of its flatness or peakedness
Term
Outlier
Definition
Extreme scores that are more than two standard deviations above or below the mean
Term
Law of Large Numbers
Definition
is a theorem that describes the result of performing the same experiment a large number of times. According to the law, the average of the results obtained from a large number of trials should be close to the expected value, and will tend to become closer as more trials are performed.
Term
Central Limit Theorem
Definition
s long as you have a reasonably large sample size (n=30) the sampling distribution of the mean will be normally distributed, even if the distribution of scores in your score sample is not.
Term
Confidence intervals
Definition
An interval calculated using sample statistics to contain the population parameter
Term
Z-Scores
Definition
# that indicates how far above or below the mean a given score in the distribution is in standard deviation units. z=individual score-mean/sd
Term
Positive Distribution/ Skew
Definition
In a skewed distribution, when most of the scores are clustered at the lower end of the distribution with a few scores creating a tail at the higher end of the distribution
Term
Descriptive Statistics
Definition
apply only to the members of the sample or the population from data collection
Term
Inferential Statistics
Definition
Statistics, derived from sample data, that are used to make inferences about the population from which the sample was drawn
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